Spark Logic

Blue Pill connection guide

Blue Pill STM32F103C8T6 Blue Pill wiring guide with power, signal assignments, and bench checks.

STM32F103C8T6 Blue Pill

49 contacts Current package

STM32F103C8T6 board · The documented blue PCB has two 20-contact headers, SWD and Micro USB. Its PC13 user LED is active low. The USB D+ pull-up varies across production boards.

Power the board from USB

Required

Use a single USB cable to power the board through its native connector. Leave external power headers disconnected. Check the 3.3 V rail before attaching the debug probe.

Bench checks

  • Identify the USB power input and ground in the board schematic.
  • Measure roughly 3.3 V between the board logic rail and ground. Check for a short or wrong connector if the rail is low.

STM32F103C8T6 Blue Pill connector map

Connection scenarios

Connect a 3.3 V UART console

Use an external 3.3 V logic-level adapter and keep the board on USB power. Cross transmit and receive, share ground and match the serial framing.

Bench checks

  • Leave the adapter’s supply output disconnected.
  • Enable USART1 on PA9/PA10 and verify that the host receives a known test string.

STM32F103C8T6 Blue Pill connector map

STM32F103C8T6 Blue Pill wiring map

Highlighted contacts are used in the required step or selected circuit. Select a contact to inspect it.

Header 1
Use the board connector marking and locate contact 1 before wiring.
Header 2
Use the board connector marking and locate contact 1 before wiring.
SWD header
Use the board connector marking and locate contact 1 before wiring.
USB connector
Use the board connector marking and locate contact 1 before wiring.
Selected pin details

H4-5 · GND

Return · Ground

Connects to the board’s ground plane.

STM32F103C8T6 Blue Pill connector map

Electrical limits · Pin in the reference

Models and documents

The maps follow the listed PCB variants. Match the board markings and connector positions to the referenced schematic before applying power.

STM32F103C8T6 Blue Pill
The documented blue PCB has two 20-contact headers, SWD and Micro USB. Its PC13 user LED is active low. The USB D+ pull-up varies across production boards.